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Title Upgrading of oil sand bitumen over an iron oxide catalyst using sub- and super-critical water

Author(s) Kondoh, Hisaki; Nakasaka, Yuta; Kitaguchi, Tatsuya; Yoshikawa, Takuya; Tago, Teruoki; Masuda, Takao

Citation Fuel Processing Technology, 145, 96-101https://doi.org/10.1016/j.fuproc.2016.01.030

Issue Date 2016-05

Doc URL http://hdl.handle.net/2115/70068

Rights © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 licensehttp://creativecommons.org/licenses/by-nc-nd/4.0/

Rights(URL) https://creativecommons.org/licenses/by-nc-nd/4.0/

Type article (author version)

File Information Upgrading of bitumen over FeOx cat_Manuscript(H.Kondoh) _f.pdf

Hokkaido University Collection of Scholarly and Academic Papers : HUSCAP

Upgrading of oil sand bitumen over an iron oxide catalyst

using sub- and super-critical water

Hisaki Kondoha, Yuta Nakasakaa,*, Tatsuya Kitaguchia, Takuya Yoshikawaa, 5

Teruoki Tagob and Takao Masudaa

a Research Group of Chemical Engineering, Division of Applied Chemistry,

Faculty of Engineering, Hokkaido University,

N13W8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan 10

b Department of Chemical Engineering, Graduate School of Engineering,

Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo,

152-8852, Japan

* Corresponding author 15

E-mail: nakasaka@eng.hokudai.ac.jp

Tel: +81-11-706-6551

Fax: +81-11-706-6552

Abstract

Upgrading of oil sand bitumen was examined using a catalyst consisting of

CeO2-ZrO2-Al2O3-FeOX and sub- and super-critical water in two reactor types:

batch-type and fixed-bed flow-type. Bitumen diluted with benzene was used as a

feedstock, and the effects of reaction pressure and temperature on product yield were 5

investigated. Under conditions of high pressure (approximately 19 MPa), catalytic

decomposition of bitumen proceeded effectively over the FeOX-based catalyst, with the

yield of lighter components such as gas oil and vacuum gas oil (VGO) reaching 70

mol%-C at a reaction temperature of 693 K. Moreover, because coke formation on the

catalyst was suppressed (less than 10 mol%-C under optimized reaction pressure and 10

temperature), the FeOX-based catalyst showed excellent durability and reusability for

catalytic decomposition of bitumen.

Keywords

Oil sand bitumen, Heavy oil, Iron oxide catalyst, Catalytic decomposition, Lighter fuel 15

1. Introduction

In recent years, the demand for useful fuels such as gasoline and kerosene has grown

constantly. According to the BP Statistical Review of World Energy, approximately half

of the Earth’s primitive petroleum deposits have already been consumed [1]. Therefore,

new techniques to produce fuels from unused heavy oil, such as atmospheric-distilled or 5

vacuum-distilled residual oil, oil sands, and Orinoco tar, are required. Oil sand bitumen,

in particular, is an important energy resource because large deposits are known to exist.

The proven reserve in Canada is estimated to be about 170 billion barrels [1]. Because

about 80% of oil sand bitumen is found in deep layers, it is recovered by the

steam-assisted gravity drainage (SAGD) method, in which high-pressure, 10

high-temperature steam is injected into the deep layer. The viscosity of bitumen mined

by the SAGD method is too high to allow transportation by pipeline, so post-mining

treatment is required to decrease the viscosity. Recently, the decomposition and

upgrading of bitumen using sub- and super-critical water, using the high-temperature,

high-pressure water used for recovery of bitumen, has attracted the attention of many 15

researchers [2-5].

Previously reported methods of upgrading heavy oil include thermal cracking [6],

hydrocracking, and catalytic cracking [7, 8]. Moreover, researchers have subjected

several types of heavy crude oil, including oil sand bitumen [9], vacuum residue [10,

11], and asphalt [12], to super-critical water treatment. They reported that super-critical

water treatment resulted in greater yields of the lighter components and smaller amounts

of coke compared to thermal decomposition.

After developing catalysts composed of iron oxide (abbreviated FeOX) supported on 5

zirconia (ZrO2), alumina (Al2O3), and ceria (CeO2) (CeO2-ZrO2-Al2O3-FeOX,

abbreviated as “FeOX-based catalyst”), we succeeded in producing lighter components

from atmospheric residual oil (AR) by catalytic cracking in a steam atmosphere [13-19].

Iron oxide has the advantage of being relatively inexpensive. Moreover, metal oxides

have been utilized in the decomposition of glycerol [20, 21], cacao pod husks [22], 10

lignin [23], pyroligneous acid [24], and ethanol fermentation stillage [25] to give useful

materials. Compared with AR, the concentration of heavy components such as VR

(vacuum residue) and asphaltenes is much higher in bitumen, which means that

carbonaceous residues and coke are easily formed during its decomposition. The

deposition of carbonaceous residue on catalysts and in reactors is a serious problem [26, 15

27]. Several methods have been proposed to overcome this problem. Cho et al. reported

a catalyst that resisted the deposition of heavy metals, and a regeneration method for

deactivated catalysts was developed [28]. Matsumura et al. reported that the formation

of carbon residues was inhibited under hydrogen at high pressure [29]. However,

hydrogen, which is produced by reforming petroleum, is expensive. Other researchers

developed an aquaconversion process for degrading heavy oil by catalytic cracking with

steam [30-32]. They reported that a catalytic steam conversion process allowed for the

transfer of hydrogen from water vapor to the unconverted crude oil bottoms. The 5

process starts with the well-known thermal cracking reaction to produce

hydrocarbon-free radicals, followed by catalytic formation of hydrogen-free radicals, as

well as hydrogen addition to the hydrocarbon-free radicals to prevent the formation of

polycondensate compounds or polymerization reactions. However, the use of

water-soluble alkali-metal-based catalysts is costly [33]. Because the use of pressurized 10

water, including sub-critical and super-critical water, was expected to suppress the

formation of coke and other residues, we examined the catalytic decomposition of

bitumen under high pressure with the aim of efficiently producing lighter fuels.

The main objective of the study was continuous decomposition of bitumen over an

FeOX-based catalyst under conditions of high-pressure water. In order to decrease the 15

amount of coke deposited on the catalyst during the reaction, the effects of reaction

pressure and temperature on the product yield and the yield of coke were investigated.

Under high-pressure conditions (approximately 19 MPa), the amount of coke deposited

on the catalyst decreased significantly. This decrease in the coke deposition was one of

the most important factors in the effective decomposition of bitumen and the durability

and reusability of the catalyst.

2. Experimental 5

2.1. Preparation and characterization of CeO2-ZrO2-Al2O3-FeOX catalyst

The CeO2-ZrO2-Al2O3-FeOX catalyst (FeOX-based catalyst) was prepared by a

co-precipitation method using Fe(NO3)3⋅9H2O, Al(NO3)3⋅9H2O, ZrO(NO3)2⋅2H2O, and

Ce(NO3)3⋅6H2O aqueous as catalyst sources. The pH of the solution was adjusted to 9.0

by addition of ammonia. All reagents were purchased from Wako Pure Chemical 10

Industries (Japan). The resulting precipitate was dried at 373 K and calcined at 773 K

for 2 h in air. The composition of the catalyst with respect to CeO2, ZrO2, and Al2O3 was

2.5, 7.5, and 7.0 wt%, respectively. The crystallinity of the catalyst prior to and after the

reaction was analyzed using an X-ray diffractometer (JDX–8020; JEOL).

15

2.2. Experimental procedure

Canadian oil sand bitumen (10 wt%) diluted with benzene to reduce the viscosity,

was used as a feedstock. The FeOX-based catalysts were confirmed in advance to be

inactive toward benzene. There was no change with benzene under each condition of the

reaction. Catalytic decomposition of bitumen using FeOX-based catalysts was carried

out in batch and fixed-bed reactors, as illustrated in Figs. 1(a) and 1(b), respectively.

[Figs. 1(a) and 1(b)]

The process in the batch reactor was as follows. The feedstock of diluted bitumen 5

was placed in the reactor along with water and the catalyst. The weight ratio of catalyst

to bitumen (Wcat /Wb, Wcat: catalyst amount [g]; Wb: weight of bitumen [g]) and water to

bitumen (WH2O/Wb, WH2O: weight of water [g]; Wb: weight of bitumen [g]) were 4 and

20, respectively. Prior to catalytic decomposition, nitrogen gas was substituted for air

inside the reactor, followed by adjustment of the initial pressure to 0.1 MPa, and the 10

valve was closed. The reactor was heated to the reaction temperature of 693 K. The

heating time and reaction time were set at 40 and 60 minutes, respectively. During the

heating process, the pressure inside the reactor increased, so the pressure was measured

and adjusted by changing the total amount of feedstock (bitumen) and water inside the

reactor. 15

The phase of the water depended on the pressure in the system at high temperature

and high pressure, which affected the catalytic decomposition of bitumen. Accordingly,

in order to optimize the pressure, its effect on the decomposition efficiency of bitumen

was examined using the batch reactor, with pressure adjusted in the range 2.9–28.3

MPa.

The process for the fixed-bed reactor was as follows. Prior to the reaction, the catalyst

was preheated under steam flow to the reaction temperature under high pressure. The

feedstock of diluted bitumen, along with water, was fed into the reactor using a 5

high-pressure pump. High-pressure water was fed from the pump into the cylinder of a

syringe and the cylinder was gradually pushed to feed the contents into the reactor. The

reaction temperature was fixed at 623–673 K, and reaction time was set to 2 h. After

termination of the reaction, the liquid and gaseous products were collected with an ice

trap and a gas pack, respectively. The time factor, which is defined as the ratio of the 10

catalyst mass to the feed rate Wcat /Fb (Wcat: catalyst amount [g], Fb: bitumen rate [g h-1]),

and FH2O/Fb (FH2O: water rate, g h-1, Fb: bitumen rate, g h-1) were 4 and 20, respectively.

The effects of reaction temperature on product yield, the decomposition efficiency of

bitumen, and the durability of the catalyst were examined.

15

2.3. Analysis

The procedure for gaseous, liquid, and solid products after experimental runs using

the batch reactor is shown in Fig. 2. Gaseous and liquid products were collected and

analyzed by gas chromatography (GC) and high-performance liquid chromatography

(HPLC), respectively. The gaseous products were analyzed by GC with thermal

conductivity and flame ionization detectors (GC-8A; Shimadzu Co. Ltd.) with activated

charcoal and Porapak Q columns, respectively. Liquid products were centrifuged to

separate the oil phase from the water phase. The resulting oil phase was analyzed by 5

HPLC using a PL-gel Mixed-D column with a refractive index (RI) detector to calculate

the molecular weight distribution. By assuming the unit structure of heavy oil to be

-CH2-, the carbon number distributions of bitumen and the resulting lighter components

were calculated from the molecular weight distribution. Because benzene was used as a

cutter stock for HPLC analysis, liquid products with a carbon number below 13 were 10

ignored in the calculation of the production yield. The carbonaceous residue remaining

on the reactor wall was almost entirely rinsed away using 40 grams of CH2Cl2. The

resulting hydrocarbon fraction in CH2Cl2 was analyzed by HPLC. The solid mixture of

catalyst and carbon was dried under vacuum conditions at 343 K and the amount of

carbon deposited on the catalyst during the reaction was analyzed using an elemental 15

analyzer (ECS 4010; Costech Analytical Technologies Inc.).

[Fig. 2]

The analytical procedure for the gaseous and liquid products obtained from the

high-pressure fixed-bed reactor was almost the same as for the products obtained in the

batch reactor. The liquid and gaseous products were collected with an ice trap and a gas

pack, respectively.

3. Results and Discussion 5

3.1 Effect of reaction pressure on product yield in the batch-type reactor

In the batch reaction system, catalytic decomposition of bitumen occurred during the

heating and cooling processes between the ambient and reaction temperatures. In order

to evaluate the decomposition activity of the catalyst, it is necessary to minimize

undesirable reactions. Accordingly, the effect of reaction time on product yield during 10

the catalytic decomposition of bitumen was examined. The reaction temperature and

pressure were 693 K and 20 MPa, respectively. The changes in product yield with time

are listed in Table 1. The products were classified into four categories: gas oil (carbon

number 14–20), VGO (21–40), VR (> 41), and coke + residue. Although CO2, methane,

and light hydrocarbons were generated as gaseous products, their total yield was less 15

than 0.1 mol%-C, so the gaseous yield was ignored.

[Table 1]

In the batch reaction system, the reactor was heated from room temperature to the

reaction temperature. Since cracking reactions as well as coke formation proceeded

during the heating process, the decomposition of bitumen and the formation of

carbonaceous residue took place only to a limited extent. After 0 min, the yield of

carbonaceous residue (coke + residue) was approximately 11.1 mol%-C; this residue

was formed during the heating process as the mixture was heated from ambient 5

temperature. The yield of lighter fuels (gas oil and VGO) increased rapidly with

reaction time up to 30 min, and increased gradually from 30 to 60 min reaction time. In

contrast, the yield of carbonaceous residue increased slightly, from 11.1 to 17.9 mol%-C,

with reaction time. Accordingly, a reaction time of 60 min was decided on for the batch

reaction. 10

Next, the effect of reaction pressure on the product yield was investigated (Fig. 3).

Although the major gaseous product was CO2, the yield was less than 0.1 mol%-C, so

the gaseous yield was ignored. As shown in the figure, the reaction pressure had a

dramatic influence on the catalytic decomposition of bitumen. The total yield of lighter

components (gas oil and VGO) reached approximately 70 mol%-C, and the formation 15

of carbonaceous residue was suppressed as the reaction pressure increased to

approximately 22 MPa. In contrast, at reaction pressures above 25.8 MPa and under

super-critical water conditions, the yield of lighter components decreased to about 45

mol%-C. Morimoto et al. reported that the polymerization of heavy oil components was

suppressed in super-critical water due to the cage effect [34]. In that experiment, heavy

components with high molecular weights were dispersed in super-critical water. Since

heavy components as well as lighter components produced in the reaction were highly

dispersed in super-critical water due to the cage effect, adsorption of these components 5

on the catalyst surface was enhanced, leading to recombination of the lighter

components and/or reaction of heavy components with the lighter components on the

catalyst surface.

[Fig. 3]

From the viewpoint of the yield of lighter components and the production of 10

carbonaceous residue, it was concluded that a reaction pressure of approximately 19

MPa was suitable for upgrading of bitumen using the FeOX-based catalyst. Next, the

effects of reaction temperature and reaction time on product yield and the stability of the

catalyst were examined using a fixed-bed reactor (19 MPa) for continuous upgrading of

bitumen over an FeOX-based catalyst. 15

3.2. Effect of reaction temperature using a fixed-bed flow-type reactor

The effect of reaction temperature on the catalytic decomposition of bitumen was

examined over an FeOX-based catalyst using a fixed-bed reactor. The reaction

temperature was varied in the range from 623 K to 693 K, and, based on the above

results, the reaction pressure was fixed at approximately 19 MPa.

Figure 4 shows the molecular weight distributions of bitumen and the liquid products.

Based on the assumption that the unit structure of heavy oil was -CH2-, the molecular 5

weight distributions (Fig. 4) were converted to the carbon number distributions for

bitumen and liquid products (Fig. 5), and these were divided into three groups (gas oil,

VGO, and VR). “Residue” and “Coke” represent the carbonaceous residue deposited on

the reactor wall and that deposited on the catalyst surface, respectively. The gaseous

products generated during the reaction, and liquid products, are also shown in Fig. 5. 10

[Fig. 4 and Fig. 5]

As shown in Figs. 4 and 5, VR (with a molecular weight above 500 g/mol) made up

approximately 65 mol%-C of the bitumen used in the reaction. Moreover, it was found

that the bitumen contained heavy components with molecular weights above 2000

g/mol. After catalytic decomposition of bitumen, the fraction of heavy components with 15

molecular weights above 2000 g/mol disappeared. Moreover, the distribution shifted

toward the lower molecular weight region, and the fractions of gas oil and VGO

(molecular weight of approximately 300 g/mol) increased significantly as the reaction

temperature increased.

As shown in Fig. 5, although the yield of residue, i.e., carbonaceous residue deposited

on the reactor wall, was approximately 20 mol%-C at reaction temperatures of 623 and

653 K, it decreased to less than 10 mol%-C at reaction temperatures above 673 K. The

decrease in the yield of residue was ascribed to the change in the viscosity of bitumen 5

with reaction temperature. The viscosity of bitumen decreased and its fluidity was

improved at temperatures above 673 K, which contributed to an increase in access to the

active site of catalyst. Under the conditions used, the heavy bitumen molecule dissolves

easily in the solvent, and the lower viscosity of the solvent improves contact between

the oil and the catalyst, resulting in a decrease in a coke formation. As shown in Figs. 10

5(a) and 5(b), the amount of CO2 generated during the reaction and the yields of lighter

components such as gas oil and VGO increased with reaction temperature. The increase

in the CO2 generation was ascribed to oxidative cracking of bitumen by the lattice

oxygen of the FeOX catalyst. Accordingly, the catalytic decomposition of bitumen

proceeded effectively over the FeOX-based catalyst at reaction temperatures above 673 15

K due to the greater fluidity of bitumen and high catalytic activity. The yields of lighter

components reached approximately 70 mol%-C at a reaction temperature of 693 K.

3.3. Catalyst durability

As discussed above, since the generation of CO2 increased at reaction temperatures

above 673 K, it was considered that the active site for the conversion of bitumen to

lighter components was the lattice oxygen of FeOX, on which the adsorbed hydrocarbon

molecules of bitumen were oxidatively decomposed into lighter components. We 5

reported previously that the lattice oxygen consumed in the reaction (defect of lattice

oxygen) can be regenerated by active oxygen species produced on ZrO2 from H2O [17,

35], and that the consumption/regeneration cycle of the lattice oxygen in FeOX

contributes to continuous activity in bitumen decomposition. Because the durability of

the catalyst is indispensable for continuous decomposition of bitumen over the 10

FeOX-based catalyst using the fixed-bed reactor, the durability of the catalyst was

examined during catalytic decomposition of bitumen. The reaction temperature and

pressure were 693 K and 19 MPa, respectively. Figures 6 and 7 show the changes in

product yield and the XRD pattern of the catalyst, respectively, with reaction time. The

product yield and the XRD pattern after the reaction under atmospheric pressure (0.1 15

MPa) are also shown in these figures for comparison.

[Fig. 6 and Fig. 7]

During the initial reaction time of 0–2 h, carbonaceous residue was deposited on the

reactor wall under both low- (0.1 MPa) and high-pressure (19 MPa) conditions. While

decomposition of bitumen occurred under low-pressure conditions, the yield of lighter

components was much lower and the coke yield was much higher than under

high-pressure conditions. Under low-pressure conditions, coke on the catalyst surface

inhibited the adsorption and reaction of the hydrocarbon molecules of bitumen on the 5

active sites, leading to a lower yield of lighter components. In contrast, suppression of

coke formation under high-pressure conditions enhanced the catalytic decomposition of

bitumen. Moreover, the total yields of gas oil and VGO were as high as 65 mol%-C

after 6 h under high-pressure conditions, indicating stable activity in the catalyst.

As shown in Fig. 7, the XRD pattern of catalyst before the reaction showed peaks 10

corresponding to hematite α-Fe2O3); almost no peaks corresponding to other metal

oxides were observed. The pattern after the reaction at low pressure showed peaks

corresponding to magnetite (Fe3O4), indicating that the FeOX in the catalyst was

reduced from hematite to magnetite during the reaction. In contrast, under high-pressure

conditions, the catalyst maintained its hematite structure for 6 h. In the catalytic 15

decomposition of bitumen, oxidative cracking of bitumen proceeded using the lattice

oxygen of FeOX. Lattice oxygen consumed during the reaction was regenerated by

active oxygen species produced by the decomposition of H2O on ZrO2 [35]. As shown

in Fig. 6, the deposition of large amounts of coke on the catalyst surface suppresses the

regeneration of the consumed lattice oxygen, leading to excessive consumption of

lattice oxygen as well as reduction of FeOX from hematite to magnetite (Fig. 7). Under

high-pressure conditions, since the consumption/regeneration reactions cycled

effectively, the catalyst maintained the hematite structure, as shown in Fig. 7. 5

After the decomposition of bitumen for 6 h, the yield of coke was approximately 10

mol%-C. This was removed from the catalyst by air calcination at 773 K for 2 h, and the

calcined catalyst was reused for catalytic decomposition of bitumen for 2 h. The product

yield and XRD pattern of the catalyst after the reaction are also shown in Figs. 6 and 7,

respectively. After air calcination, the catalyst gave almost the same product yield and 10

exhibited almost the same XRD pattern as before air calcination. Accordingly, the

FeOX-based catalyst showed excellent durability during the catalytic decomposition of

bitumen.

4. Conclusion 15

Upgrading of Canadian oil sand bitumen over an FeOx-based catalyst was examined

with the aim of producing lighter fuels. It was revealed that the catalytic decomposition

of bitumen proceeded effectively under high-pressure conditions (around 19 MPa) with

low coke deposition on the catalyst. Moreover, the yield of lighter components (gas oil

and VGO) reached approximately 70 mol%-C, and continuous decomposition of

bitumen with high yields was achieved using a fixed-bed reactor. Since the amount of

coke deposited on the catalyst was as low as 10 mol%-C under optimized conditions

(reaction temperature and pressure of 693 K and 19 MPa, respectively), the FeOX-based 5

catalyst showed excellent durability and reusability for catalytic decomposition of

bitumen.

5. Acknowledgements

This research was supported by the Japan Petroleum Energy Center (JPEC) as part of 10

a technological development project financially supported by the Ministry of Economy,

Trade, and Industry.

Fig. 1 Experimental apparatus for catalytic decomposition of bitumen.

(a) High-pressure batch reactor; (b) high-pressure fixed-bed flow reactor.

Fig. 2 Analytical procedure for products after decomposition of bitumen using batch

reactor. 5

Fig. 3 Effect of reaction pressure on product yield for catalytic decomposition of

bitumen over FeOX-based catalyst using a batch reactor. Reaction conditions: 10 wt%

bitumen solution, Wcat /Wb = 4, WH2O /Wb = 20, P (reaction pressure) = 2.9–28.3 MPa, T

(reaction temperature) = 693 K, and t (reaction time) = 60 min. 10

Fig. 4 Changes in the molecular weight distribution of bitumen and liquid products

with reaction temperature during catalytic decomposition of bitumen using a fixed-bed

flow reactor. Reaction conditions: 10 wt% bitumen solution, Wcat /Fb = 4, FH2O /Fb = 20,

reaction pressure ~19 MPa. 15

Fig. 5 Changes in (a) amount of gaseous products generated, and (b) yield of liquid

product with reaction temperature during catalytic decomposition of bitumen using a

fixed-bed flow reactor. Reaction conditions: 10 wt% bitumen solution, Wcat /Fb = 4,

FH2O /Fb = 20, P (reaction pressure) = 19 MPa, T (reaction temperature) = 623–693 K,

and t (reaction time) = 2 h.

Fig. 6 Changes in product yields with time on stream during catalytic decomposition 5

of bitumen using a fixed-bed flow reactor. Reaction conditions: 10 wt% bitumen

solution, Wcat /Fb = 4, FH2O /Fb = 20, reaction pressure ~19 MPa.

Fig. 7 XRD patterns of catalysts prior to and after the reaction with different reaction

times. Reaction conditions: 10 wt% bitumen solution, Wcat /Fb = 4, FH2O /Fb = 20, 10

reaction pressure ~19 MPa.

Table 1 Changes in product yield with reaction time during catalytic decomposition of

bitumen over an FeOX-based catalyst using a batch reactor. Reaction conditions: 10

wt% bitumen solution, Wcat /Wb = 4, WH2O /Wb = 20, P (reaction pressure) = 20 MPa, T 15

(reaction temperature) = 693 K, and t (reaction time) = 0–60 min.

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30

Upgrading of oil sand bitumen over iron oxide catalyst

using sub- and super-critical water

Fig.

Fig. 1 Experimental apparatus for catalytic decomposition of bitumen.

(a) High-pressure batch reactor; (b) high-pressure fixed-bed flow reactor.

Fig. 2 Analytical procedure for products after decomposition of bitumen using batch reactor.

*) Add 40 grams CH2Cl2, extract by ultra sonic wave for 1 hour, and still standing over night

Residue in reactor

Products

Gas GC-TCD GC-FID

Liquid HPLC

HPLC

CH2Cl2 fraction

Residue + catalyst

Extraction of heavy component

Vacuum drying

**)E.A. & XRD

CH2Cl2 fraction Catalyst **) E.A. = elemental analysis

Filtering

*)CH2Cl2

Fig. 3 Effect of reaction pressure on product yield for catalytic decomposition of bitumen over FeOX-based catalyst using a batch reactor. Reaction condition: 10 wt% bitumen solution, Wcat /Wb = 4, WH2O /Wb = 20, P (Reaction pressure) = 2.9–28.3 MPa, T (Reaction temperature) = 693 K, and t (Reaction time) = 60 min.

Gas

Coke + Residue

Gas Oil

VGO

VR

Bitumen 2.9 8.6 18.9 21.7 22.3 25.8 26.9 28.3 Pressure [MPa]

0

20

40

60

80

100

Car

bon

yiel

d [m

ol%

-C]

Feed

M.W. [g･mol-1]

Gas Oil VGO VR

0

0.2

0.4

0.6

0.8

102 103 104 105

673 K

693 K

653 K

623 K

Yie

ld o

f eac

h M

. W.

[(m

ol%

-C)/(

g･m

ol-1

)]

Fig. 4 Changes in the molecular weight distribution of bitumen and liquid products with reaction temperature during catalytic decomposition of bitumen using a fixed-bed flow reactor. Reaction condition: 10 wt% bitumen solution, Wcat /Fb = 4, FH2O /Fb = 20, Reaction pressure was ~19 MPa.

Fig. 5 Changes in (a) amount of gaseous products generated, and (b) yield of liquid product with reaction temperature during catalytic decomposition of bitumen using a fixed-bed reactor. Reaction condition: 10 wt% bitumen solution, Wcat /Fb = 4, FH2O /Fb = 20, P (Reaction pressure) = 19 MPa, T (Reaction temperature) = 623-693 K, and t (Reaction time) = 2 h.

Bitumen 653 673 623 Reaction temperature [K]

693 No catalyst (693)

0

20

40

60

80

100

Car

bon

yiel

d [m

ol%

-C]

Gas Oil

VGO

VR

Coke

Gas

Residue 5(b)

Am

ount

of g

aseo

us p

rodu

cts

[10-4

mol

/g-o

il]

0 2 4 6 8

10 12 14 16 18

CO2

CH4

Paraffin

H2

Olefin 5(a)

Car

bon

yiel

d [m

ol%

-C]

Residue

0

20

40

60

80

100

Bitumen 2~4 h

Gas Oil

VGO

VR Coke

Gas

0~2 h

Reaction time [h]

4~6 h 0~2 h

19 MPa 0.1 MPa

After air-calcination 0~2 h

Fig. 6 Changes in product yields with time on stream during catalytic decomposition of bitumen using a fixed-bed flow reactor. Reaction condition: 10 wt% bitumen solution, Wcat /Fb = 4, FH2O /Fb = 20, Reaction pressure was ~19 MPa.

Fig. 7 XRD patterns of catalysts prior to and after the reaction with different reaction times. Reaction condition: 10 wt% bitumen solution, Wcat /Fb = 4, FH2O /Fb = 20, Reaction pressure was ~19 MPa.

Upgrading of oil sand bitumen over iron oxide catalyst

using sub- and super-critical water

Table

Table 1 Changes in product yield with reaction time during the catalytic decomposition of bitumen over FeOx-based catalyst with a batch reactor. Reaction condition: 10 wt% bitumen solution, Wcat /Wb = 4, WH2O /Wb = 20, P (Reaction pressure) = 20 MPa, T (Reaction temperature) = 693 K, and t (Reaction time) = 0–60 min.

Carbon yield [mol%-C]

Gas Oil VGO VR Coke + Residue

Reaction time [min.]

36.8 17.5 0 11.1 19.6 27.1 40.6 15 12.7 15.2 31.4 38.1 30 15.3 9.3 35.3 37.2 60 17.9

32.6 22.0 41.5 3.9

34.6

60 (Without catalyst)